informal an indication of satisfaction or approval (or of rejection or failure)
〈非正式〉赞同; 赞赏, 满意（或否定、排斥、反对、拒绝、抛弃）：
plans to build a house on the site have been given the thumbs down by the Department of the Environment.
环境部反对在这个地方建房的计划。
ORIGIN: with reference to the signal of approval or disapproval, used by spectators at a Roman amphitheatre; the sense has been reversed, as the Romans used 'thumbs down' to signify that a beaten gladiator had performed well and should be spared, and 'thumbs up' to call for his death.